Abstract:
Take an LED that produces intense, blue light. Coat it with a thin layer of special microscopic beads called quantum dots. And you have what could become the successor to the venerable light bulb.

The resulting hybrid LED gives off a warm white light with a slightly yellow cast, similar to that of the incandescent lamp.

Until now quantum dots have been known primarily for their ability to produce a dozen different distinct colors of light simply by varying the size of the individual nanocrystals: a capability particularly suited to fluorescent labeling in biomedical applications. But chemists at Vanderbilt University discovered a way to make quantum dots spontaneously produce broad-spectrum white light. The report of their discovery, which happened by accident, appears in the communication "White-light Emission from Magic-Sized Cadmium Selenide Nanocrystals" published online October 18 by the Journal of the American Chemical Society.